Field of the Invention
This invention relates generally to an aerodynamic force sensing apparatus for providing an air data computer with information to calculate air data, e.g., angle of attack, sideslip angle, dynamic pressure, and/or airspeed.
Description of the Related Art including Information Disclosed under 37 CFR 1.97 and 1.98
Micro air vehicles (MAVs) present special problems for air data calculation because they operate in the near-earth, below rooftop/tree-top environment where chaotic turbulence is common. A MAV may be in a severe downdraft at one moment, a tailwind the next, and an updraft after that. Yet MAVs are so small and light that conventional sensor systems are too heavy and/or bulky and unsuited for accurate operation at the slow airspeeds at which MAVs typically operate. Small, lightweight sensors capable of providing accurate information to an air data computer (ADC), even at low airspeeds, would enable a MAV aerodynamic control system to respond and compensate more rapidly and effectively to gusts, updrafts, downdrafts, wind shears, and other phenomena affecting aerodynamic stability and control.
Aerodynamic force sensors are known for use in providing air vehicle onboard air data computers (ADCs) with information that ADCs need to calculate air data, e.g., angle of attack, sideslip angle, dynamic pressure, and/or airspeed. Known aerodynamic force sensors include angle-of-attack (AOA) sensors, angle-of-slip (AOS) sensors, and wingtip vortex angle sensors, with AOA being defined as the acute angle between the chord of an airfoil and a line representing the undisturbed relative airflow or relative wind, AOS being defined as the acute angle between an aircraft centerline and a line representing the relative wind, and vortex angle being defined as the angle between a circular vortical helix and its vortical axis.
It's also known for glider-type aircraft to comprise bird-like wings and arrays of wingtip feather-like structures. Also, radio-controlled bird models are known to include pivotably-mounted tip feather arrays actuable to provide active aerodynamic control of the models.